Indoor and outdoor relationships of CO concentrations in natural ventilating rooms in summer, Shanghai

The time series of indoor and outdoor CO concentrations in natural ventilating rooms were monitored continuously and simultaneously in summer, and the relationships between indoor and outdoor CO concentrations at two sampling locations in the central area of Shanghai were examined and discussed. Linear regression analysis was employed to correlate indoor concentration levels with outdoor concentrations, and the diurnal cycles of the indoor and outdoor CO concentrations show positive correlations at both sampling sites. The monitoring data also indicate that the indoor to outdoor ratios of CO concentrations in the test natural ventilating rooms are less than but close to 1. In addition, a predicting model based on a mass balance assumption of indoor pollutants was applied for estimating the indoor CO concentrations by using the outdoor test data as inputs, resulting in good agreement with the test curves for the two sampling sites.